hmmm...i don't think ive seen exactly what ichijou's power is in the manga.

but he does wield a sword, right? it's the one he used to splice that vampire attacking shiki and rima in chap41, and that time when he was ordered by kaname to kill a level e outside cross academy grounds.

i haven't seen what ruka and seiren's powers are, too. maybe they'll come up later as the story progresses (especially since they'll be fighting rido now).